kotlin-coroutines-flows

Use coroutineScope with multiple async blocks to run suspending work concurrently, then call await on each Deferred result. This keeps the work structured so the parent scope waits for all children and propagates failures correctly.

Call stateIn on the Flow with viewModelScope, SharingStarted.WhileSubscribed(5000), and an initial value. The WhileSubscribed timeout keeps the upstream active briefly after subscribers leave, surviving configuration changes.

Use StateFlow for UI state that always has a current value and should be replayed to new collectors. Use SharedFlow for one-time events like snackbars or navigation that should not be re-delivered after rotation.

Dispatchers.IO is only available on JVM and Android. In KMP shared code, use Dispatchers.Default or Dispatchers.Main, which exist on all platforms, or inject the IO dispatcher through dependency injection.

Wrap the StateFlow collection in flow.test inside a runTest block, then assert each awaitItem emission in order. Turbine fails the test if unexpected emissions occur or expected ones never arrive.

GlobalScope launches coroutines with no parent, so they are never cancelled when the associated lifecycle ends, causing leaks. Use viewModelScope, lifecycleScope, or a custom structured scope tied to the component lifetime.